The MPLS Traffic Engineering—LSP Attributes feature is an extension to MPLS TE that provides an LSP Attribute List feature and a Path Option for Bandwidth Override feature. These features provide flexibility in the configuration of LSP attributes for MPLS TE tunnel path options. Several LSP attributes can be applied to path options for TE tunnels using an LSP attribute list. If bandwidth is the only LSP attribute you require, then you can configure a path option for bandwidth override.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for MPLS Traffic Engineering—LSP Attributes" section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for MPLS Traffic Engineering—LSP Attributes

TheMPLS Traffic Engineering—LSP Attributes feature requires that you configure an MPLS TE tunnel before you configure either an LSP Attribute List or a Path Option for Bandwidth Override feature.

Restrictions for MPLS Traffic Engineering—LSP Attributes

Reoptimization between path options with different bandwidth pool types (subpool versus global pool) and different priorities is not supported. Specifically,

•With the Path Option for Bandwidth Override feature, you need to configure bandwidth for path options with the same bandwidth pool as configured for the tunnel.

•With the LSP Attribute List feature, you need to configure both a bandwidth pool and priority for path options that are consistent with the bandwidth pool and priority configured on the tunnel or in other path options used by the tunnel.

Information About MPLS Traffic Engineering—LSP Attributes

To configure the MPLS Traffic Engineering—LSP Attributes feature, you need the following information:

•One or more TE tunnels can specify specific path options by referencing an LSP attribute list.

•LSP attribute lists make the MPLS TE user interface more flexible, easier to use, and easier to extend and maintain.

•The Path Option for Bandwidth Override feature provides a single command that allows a TE tunnel to fall back temporarily to path options that can reduce bandwidth constraints.

Traffic Engineering Bandwidth and Bandwidth Pools

MPLS traffic engineering allows constraint-based routing (CBR) of IP traffic. One of the constraints satisfied by CBR is the availability of required bandwidth over a selected path. Regular TE tunnel bandwidth is called the global pool. Subpool bandwidth is a portion of the global pool. Subpool bandwidth is not reserved from the global pool if it is not in use. Therefore, subpool tunnels require a higher priority than nonsubpool tunnels.

You can configure the LSP Attributes bandwidth path option to use either global pool (default) or subpool bandwidth. The bandwidth value for the path option may be any valid value and the pool does not have to be the same as that configured on the tunnel.

Note When you configure bandwidth for path options with the bandwidth [sub-pool | global] kbps command, use either all subpool bandwidths or all global-pool bandwidths.

You can configure bandwidth on both dynamic and explicit path options using either the LSP Attribute List feature or the Path Option for Bandwidth Override feature. The commands that enable these features are exclusive of each other. If bandwidth is the only LSP attribute that you need to set on the path option, then use the command to enable the Path Option for Bandwidth Override feature. This is the simplest way to configure multiple path options with decreasing bandwidth constraints. Once the bandwidth keyword is entered on the tunnel mpls traffic-eng path-option command in interface configuration mode, you cannot configure an LSP attribute list for that path option.

LSP Attribute Lists Usage and Management

This section contains the following topics about LSP attribute lists usage and management:

Tunnel Attributes and LSP Attributes

Cisco IOS tunneling interfaces have many parameters associated with MPLS TE. Typically, you configure these parameters with tunnel mpls traffic-eng commands in interface configuration mode. Many of these commands determine tunnel-specific properties, such as the load-sharing factor for the tunnel. These commands configure parameters that are unrelated to the particular LSP in use by the tunnel. However, some of the tunneling parameters apply to the LSP that the tunnel uses. You can configure the LSP-specific properties using an LSP attribute list.

LSP Attributes and the LSP Attribute List

An LSP attribute list can contain values for each LSP-specific parameter that is configurable for a TE tunnel. You configure an LSP attribute list with the mpls traffic-eng lsp attributesstring command, where string identifies the attribute list. The LSP attributes that you can specify include the following:

•Attribute flags for links that make up the LSP (affinity command)

•Automatic bandwidth configuration (auto-bw command)

•LSP bandwidth—global pool or subpool (bandwidth command)

•Disable reoptimization of the LSP (lockdown command)

•LSP priority (priority command)

•Protection failure (protection command)

•Record the route used by the LSP (record-route command)

LSP Attribute Lists Management

The MPLS Traffic Engineering—LSP Attributes feature also provides commands that help you manage LSP attribute lists. You can do the following:

•Relist all attribute list entries (list command)

•Remove a specific attribute from the list (noattribute command)

The exit command exits from the LSP attributes configuration submode and returns you to global configuration mode.

Based on your requirements, you can configure LSP attributes lists with different sets of attributes for different path options. LSP attribute lists also provide an easy way to configure multiple TE tunnels to use the same LSP attributes. That is, you can reference the same LSP attribute list to configure LSP-specific parameters for one or more TE tunnels.

Autobandwidth and Path Option for Bandwidth Override

If Traffic Engineering automatic bandwidth (autobandwidth) adjustment is configured for a tunnel, traffic engineering automatically adjusts the bandwidth allocation for the traffic engineering tunnel based on its measured usage of the bandwidth of the tunnel.

Traffic engineering autobandwidth samples the average output rate for each tunnel marked for automatic bandwidth adjustment. For each marked tunnel, it periodically adjusts the allocated bandwidth for the tunnel to be the largest sample for the tunnel since the last adjustment. The default reoptimization setting in the MPLS AutoBandwidth feature is every 24 hours

The frequency with which tunnel bandwidth is adjusted and the allowable range of adjustments is configurable on a per-tunnel basis. In addition, the sampling interval and the interval over which to average tunnel traffic to obtain the average output rate is user-configurable on a per-tunnel basis.

For more information on automatic bandwidth adjustment for TE tunnels, see the MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels feature documentation.

The Path Option for Bandwidth Override feature allows you to override the bandwidth configured on a TE tunnel. This feature also overrides bandwidth configured or recalculated by automatic bandwidth adjustment if the path option in effect has bandwidth override enabled.

Path Option Selection for MPLS TE Tunnel LSPs

This section contains the following topics about path option selection for MPLS TE Tunnel LSPs:

Constraint-Based Routing and Path Option Selection

MPLS traffic engineering automatically establishes and maintains LSPs across the backbone by using the Resource Reservation Protocol (RSVP). The path that an LSP uses is determined by the LSP resource requirements and network resources, such as bandwidth. Traffic engineering tunnels are calculated at the LSP head based on a fit between required and available resources (constraint-based routing).

Without the Path Option for Bandwidth Override feature, a TE tunnel establishes an LSP based on dynamic or explicit path options in order of preference. However, the bandwidth and other attributes configured on the TE tunnel allow the setup of an LSP only if LSP path options satisfy the constraints. If a path cannot be found that satisfies the configured path options, then the tunnel is not set up.

The Path Option for Bandwidth Override feature provides a fallback path option that allows overriding the bandwidth configured on the TE tunnel interface. For example, you can configure a path option that sets the bandwidth to zero (0) effectively removing the bandwidth constraint imposed by the constraint-based routing calculation.

Tunnel Reoptimization and Path Option Selection

Reoptimization occurs when a device with traffic engineering tunnels periodically examines tunnels with established LSPs to learn if better LSPs are available. If a better LSP seems to be available, the device attempts to signal the better LSP. If the signaling is successful, the device replaces the older LSP with the new, better LSP.

Reoptimization can be triggered by a timer, the issuance of an mpls traffic-eng reoptimize command, or a configuration change that requires the resignalling of a tunnel. The MPLS AutoBandwidth feature, for example, uses a timer to set the frequency of reoptimization based on the bandwidth path option attribute. The Path Option for Bandwidth Override feature allows for the switching between bandwidth configured on the TE tunnel interface and bandwidth configured on a specific path option. This increases the success of signaling an LSP for the TE tunnel.

You can disable reoptimization of an LSP with the lockdown command in an LSP attribute list. You can apply the LSP attribute list containing the lockdown command to a path option with the tunnel mpls traffic-eng path-option command.

Note When you configure bandwidth for path options with the bandwidth [sub-pool | global] kpbs command, use either all subpool bandwidths or all global-pool bandwidths. Do not mix subpool and nonsubpool bandwidths, otherwise the path option does not reoptimize later.

Path Option Selection with Bandwidth Override

The Path Option for Bandwidth Override feature allows you to configure bandwidth parameters on a specific path option with the bandwidth keyword on the tunnel mpls traffic-eng path-option command. When an LSP is signaled using a path option with a configured bandwidth, the bandwidth associated with the path option is signaled instead of the bandwidth configured directly on the tunnel.

This feature provides you with the ability to configure multiple path options that reduce the bandwidth constraint each time the headend of a tunnel fails to establish an LSP.

The following configuration shows three tunnel mpls traffic-eng path-option commands:

Configuring an LSP Attribute List

Perform this task to configure a label switched path (LSP) attribute list with the desired attributes to be applied on a path option. Based on your requirements, you can configure LSP attributes lists with different sets of attributes for different path options. The LSP attribute list provides a user interface that is flexible, easy to use, and easy to extend and maintain for the configuration of MPLS TE tunnel path options.

LSP attribute lists also provide an easy way to configure multiple TE tunnels to use the same LSP attributes. That is, you can reference the same LSP attribute list to configure LSP-specific parameters for one or more TE tunnels.

–If a bit in the mask is 0, an attribute value of the link for that bit is irrelevant.

–If a bit in the mask is 1, the attribute value of that link and the required affinity of the LSP for that bit must match.

Step 5

auto-bw [frequencysecs] [max-bwkbps] [min-bw kbps] [collect-bw]

Example:

Router(config-lsp-attr)# auto-bw

(Optional) Specifies automatic bandwidth configuration.

•The frequencysecs keyword argument combination specifies the interval between bandwidth adjustments. The specified interval can be from 300 to 604800 seconds.

•The max-bw kbps keyword argument combination specifies the maximum automatic bandwidth, in kbps, for this path option. The value can be from 0 to 4294967295.

•The min-bwkbps keyword argument combination specifies the minimum automatic bandwidth, in kbps, for this path option. The value can be from 0 to 4294967295.

•The collect-bw keyword collects output rate information for the path option, but does not adjust the bandwidth of the path option.

Step 6

bandwidth [sub-pool | global] kbps

Example:

Router(config-lsp-attr)# bandwidth 5000

(Optional) Specifies LSP bandwidth.

•The sub-pool keyword indicates a subpool path option.

•The global keyword indicates a global pool path option. Entering this keyword is not necessary, for all path options are from the global pool in the absence of the sub-pool keyword.

•The kbps argument is the number of kilobits per second set aside for the path option. The range is from 1 to 4294967295.

Step 7

list

Example:

Router(config-lsp-attr)# list

(Optional) Displays the contents of the LSP attribute list.

Step 8

lockdown

Example:

Router(config-lsp-attr)# lockdown

(Optional) Disables reoptimization of the LSP.

Step 9

prioritysetup-priority [hold-priority]

Example:

Router(config-lsp-attr)# priority 1 1

(Optional) Specifies the LSP priority.

•The setup-priority argument is used when signaling an LSP to determine which existing LSPs can be preempted. Valid values are from 0 to 7, where a lower number indicates a higher priority. Therefore, an LSP with a setup priority of 0 can preempt any LSP with a non-0 priority.

•The hold-priority argument is associated with an LSP to determine if it should be preempted by other LSPs that are being signaled. Valid values are from 0 to 7, where a lower number indicates a higher priority.

Step 10

protectionfast-reroute

Example:

Router(config-lsp-attr)# protection fast-reroute

(Optional) Enables failure protection on the LSP.

Step 11

record-route

Example:

Router(config-lsp-attr)# record-route

(Optional) Records the route used by the LSP.

Step 12

no sub-command

Example:

Router(config-lsp-attr)# no record-route

(Optional) Removes a specific attribute from the LSP attributes list.

•The sub-command argument names the LSP attribute to remove from the attributes list.

Step 13

exit

Example:

Router(config-lsp-attr)# exit

(Optional) Exits from LSP Attributes configuration mode.

Step 14

end

Example:

Router(config)# end

(Optional) Exits to privileged EXEC mode.

Adding Attributes to an LSP Attribute List

Perform this task to add attributes to an LSP attribute list. The LSP attribute list provides a user interface that is flexible, easy to use, and that can be extended or changed at any time to meet the requirements of your MPLS TE tunnel traffic. LSP Attributes configuration mode is used to display the specific LSP attributes list and to add or change the required path option attribute.

–If a bit in the mask is 0, an attribute value of the link or that bit is irrelevant.

–If a bit in the mask is 1, the attribute value of that link and the required affinity of the LSP for that bit must match.

Step 5

bandwidth [sub-pool | global] kbps

Example:

Router(config-lsp-attr)# bandwidth 1000

Specifies an LSP bandwidth.

•The sub-pool keyword indicates a subpool path option.

•The global keyword indicates a global pool path option. Entering this keyword is not necessary, for all path options are from the global pool in the absence of the sub-pool keyword.

•The kbps argument is the number of kilobits per second set aside for the path option. The range is from 1 to 4294967295.

Step 6

prioritysetup-priority [hold-priority]

Example:

Router(config-lsp-attr)# priority 2 2

Specifies the LSP priority.

•The setup-priority argument is used when signaling an LSP to determine which existing LSPs can be preempted. Valid values are from 0 to 7, where a lower number indicates a higher priority. Therefore, an LSP with a setup priority of 0 can preempt any LSP with a non-0 priority.

•The hold-priority argument is associated with an LSP to determine if it should be preempted by other LSPs that are being signaled. Valid values are from 0 to 7, where a lower number indicates a higher priority.

Step 7

list

Example:

Router(config-lsp-attr)# list

(Optional) Displays the contents of the LSP attribute list.

•Use the list command to display the path option attributes added to the attribute list.

Step 8

exit

Example:

Router(config-lsp-attr)# exit

(Optional) Exits LSP Attributes configuration mode.

Step 9

end

Example:

Router(config)# end

(Optional) Exits to privileged EXEC mode.

Removing an Attribute from an LSP Attribute List

Perform this task to remove an attribute from an LSP attribute list. The LSP attributes list provides a means to easily remove a path option attribute that is no longer required for your MPLS TE tunnel traffic. LSP Attributes configuration mode is used to display the specific LSP attribute list and for the no sub-command command, which is used to remove the specific attribute from the list. Replace the sub-command argument with the command that you want to remove from the list.

•The sub-command argument names the LSP attribute to remove from the attributes list.

Step 5

list

Example:

Router(config-lsp-attr)# list

(Optional) Displays the contents of the LSP attribute list.

•Use the list command to verify that the path option attribute is removed from the attribute list.

Step 6

exit

Example:

Router(config-lsp-attr)# exit

(Optional) Exits LSP Attributes configuration mode.

Step 7

end

Example:

Router(config)# end

(Optional) Exits to privileged EXEC mode.

Modifying an Attribute in an LSP Attribute List

Perform this task to modify an attribute in an LSP attribute list. The LSP attribute list provides a flexible user interface that can be extended or modified an any time to meet the requirements of your MPLS TE tunnel traffic. LSP Attributes configuration mode is used to display the specific LSP attributes list and to modify the required path option attribute.

•Use the show mpls traffic-eng lsp attributes command to verify that the LSP attribute list was deleted from the router.

Verifying Attributes Within an LSP Attribute List

SUMMARY STEPS

1. enable

2. configureterminal

3. mpls traffic-eng lsp attributes string list

4. exit

5. end

DETAILED STEPS

Step 1 enable

Use this command to enable privileged EXEC mode. Enter your password if prompted. For example:

Router> enable

Router#

Step 2 configure terminal

Use this command to enter global configuration mode. For example:

Router# configure terminal

Router(config)#

Step 3 mpls traffic-eng lsp attributesstringlist

Use this command to enter LSP Attributes configuration mode for a specific LSP attribute list and to verify that the contents of the attributes list are as expected. For example:

Router(config)# mpls traffic-eng lsp attributes 1 list

LIST 1

bandwidth 1000

priority 1 1

Step 4 exit

Use this command to exit LSP Attributes configuration mode. For example:

Router(config-lsp-attr)# exit

Router(config)#

Step 5 end

Use this command to exit to privileged EXEC mode. For example:

Router(config)# exit

Router#

Verifying All LSP Attribute Lists

Perform this task to verify all configured LSP attribute lists. Use this task to display all LSP attribute lists to verify that the attributes lists that you configured are in operation.

SUMMARY STEPS

1. enable

2. show mpls traffic-eng lsp attributes [string][details]

3. show running-config | begintext-string

4. exit

DETAILED STEPS

Step 1 enable

Use this command to enable privileged EXEC mode. Enter your password if prompted. For example:

Router> enable

Router#

Step 2 show mpls traffic-eng lsp attributes [string][details]

Use this command to verify that all configured LSP attribute lists are as expected. For example:

Router# show mpls traffic-eng lsp attributes

LIST 1

affinity 1 mask 1

bandwidth 1000

priority 1 1

LIST 2

bandwidth 5000

LIST hipriority

priority 0 0

!

Step 3 show running-config | begintext-string

Use this command to verify that all configured LSP attribute lists are as expected. Use the begin command modifier with the mpls traffic-eng lsptext-string to locate the LSP attributes information in the configuration file. For example:

Router# show running-config | begin mpls traffic-eng lsp

mpls traffic-eng lsp attributes 1

affinity 1 mask 1

bandwidth 1000

priority 1 1

!

mpls traffic-eng lsp attributes 2

bandwidth 5000

!

mpls traffic-eng lsp attributes hipriority

priority 0 0

.

.

.

Router#

Step 4 exit

Use this command to exit to user EXEC mode. For example:

Router# exit

Router>

Associating an LSP Attribute List with a Path Option for an MPLS TE Tunnel

Perform this task to associate an LSP attribute list with a path option for an MPLS TE tunnel. This task is required if you want to apply the LSP attribute list that you configured to path options for your MPLS TE tunnels.

Based on your requirements, you can configure LSP attributes lists with different sets of attributes for different path options. LSP attribute lists also provide an easy way to configure multiple TE tunnels to use the same LSP attributes. That is, you can reference the same LSP attribute list to configure LSP-specific parameters for one or more TE tunnels.

Values for path option attributes for a TE tunnel are determined in this manner:

•LSP attribute list values referenced by the path option take precedence over the values configured on the tunnel interface.

•If an attribute is not specified in the LSP attribute list, the device uses the attribute in the tunnel configuration. LSP attribute lists do not have defaults.

•If the attribute is not configured on the tunnel, then the device uses the tunnel default value, as follows:

•The global keyword indicates a global pool path option. Entering this keyword is not necessary, for all path options are from the global pool in the absence of the sub-pool keyword.

•The kbps argument is the number of kilobits per second set aside for the path option. The range is from 1 to 4294967295.

•The lockdown keyword disables reoptimization of the LSP.

Step 10

end

Example:

Router(config-if)# end

(Optional) Exits to privileged EXEC mode.

Modifying a Path Option to Use a Different LSP Attribute List

Perform this task to modify the path option to use a different LSP attribute list.

Based on your requirements, you can configure LSP attributes lists with different sets of attributes for different path options or change the set of attributes associated with a path option. You use the tunnel mpls traffic-eng path-option numberdynamic attributesstring command in interface configuration mode to modify the path option to use a different LSP attribute list. The attributesstring keyword and argument names the new LSP attribute list for the path option specified.

Note Once you configure bandwidth as a path-option parameter, you can no longer configure an LSP attribute list as a path-option parameter.

Configuring Fallback Bandwidth Path Options for TE Tunnels

Perform this task to configure fallback bandwidth path options for a TE tunnel. Use this task to configure path options that reduce the bandwidth constraint each time the headend of a tunnel fails to establish an LSP.

Configuration of the Path Option for Bandwidth Override feature can reduce bandwidth constraints on path options temporarily and improve the chances that an LSP is set up for the TE tunnel. When a TE tunnel uses a path option with bandwidth override, the traffic engineering software attempts every 30 seconds to reoptimize the tunnel to use the preferred path option with the original configured bandwidth. The Path Option for Bandwidth Override feature is designed as a temporary reduction in bandwidth constraint. To force immediate reoptimization of all traffic engineering tunnels, you can use the mpls traffic-eng reoptimize command. You can also configure the lockdown command with bandwidth override to prevent automatic reoptimization.

•The global keyword indicates a global pool path option. Entering this keyword is not necessary, for all path options are from the global pool in the absence of the sub-pool keyword.

•The kbps argument is the number of kilobits per second set aside for the path option. The range is from 1 to 4294967295.

•The lockdown keyword disables reoptimization of the LSP.

Step 6

end

Example:

Router(config-if)# end

(Optional) Exits to privileged EXEC mode.

Modifying the Bandwidth on a Path Option for Bandwidth Override

Perform this task to modify the bandwidth on a path option for bandwidth override. You might need to further reduce or modify the bandwidth constraint for a path option to ensure that the headend of a tunnel establishes an LSP.

The Path Option for Bandwidth Override feature is designed as a temporary reduction in bandwidth constraint. To force immediate reoptimization of all traffic engineering tunnels, you can use the mpls traffic-eng reoptimize command. You can also configure the lockdown command with bandwidth override to prevent automatic reoptimization.

•The global keyword indicates a global pool path option. Entering this keyword is not necessary, for all path options are from the global pool in the absence of the sub-pool keyword.

•The kbps argument is the number of kilobits per second set aside for the path option. The range is from 1 to 4294967295.

•The lockdown keyword disables reoptimization of the LSP.

Step 6

end

Example:

Router(config-if)# end

(Optional) Exits to privileged EXEC mode.

Step 7

show mpls traffic-eng tunnelstunnel-interface [brief]

Example:

Router# show mpls traffic-eng tunnels tunnel1

(Optional) Displays information about tunnels.

•Use the show mpls traffic-eng tunnels command to verify which bandwidth path option is in use by the LSP.

Removing a Path Option for Bandwidth Override

Perform this task to remove the bandwidth on the path option for bandwidth override. The Path Option for Bandwidth Override feature is designed as a temporary reduction in bandwidth constraint. Use this task to remove the bandwidth override when it is not required.

If bandwidth override is actively being signaled, the show mpls traffic-eng tunnel command displays the bandwidth override information under the Active Path Option Parameters heading. The example shows that BandwidthOverride is enabled and that the tunnel is signaled using path-option 2. The bandwidth signaled is 500. This is the value configured on the path option 2 and it overrides the 1000 kbps bandwidth configured on the tunnel interface.

Step 3 exit

Use this command to exit to user EXEC mode. For example:

Router# exit

Router>

Troubleshooting Tips

If the tunnel state is down and you configured a path-option with bandwidth override enabled, the show mpls traffic-eng tunnels command indicates other reasons why a tunnel is not established. For example:

•The tunnel destination is not in the routing table.

•If the bandwidth override value is not zero, the bandwidth constraint may still be too large.

•Other attributes configured on the tunnel, such as affinity, might prevent the calculation of a path over the existing topology.

•TE might not be configured on all links necessary to reach tunnel destination.

Configuration Examples for MPLS Traffic Engineering—LSP Attributes

This section contains the following configuration examples for the MPLS Traffic Engineering—LSP Attributes features:

The device attempts to signal an LSP with the 1000 kbps bandwidth configured on the tunnel interface because path-option 1 has no bandwidth configured.

•If 1000 kbps bandwidth is not available over the network, the device attempts to establish an LSP using path-option 2.

Path-option 2 has a bandwidth of 500 kbps configured. This reduces the bandwidth constraint from the original 1000 kbps configured on the tunnel interface.

•If 500 kbps is not available, the device attempts to establish an LSP using path-option 3.

Path-option 3 is configured as dynamic and has bandwidth 0. The device establishes the LSP if an IP path exists to the destination and all other tunnel constraints are met.

Modifying the Bandwidth on a Path Option for Bandwidth Override: Example

The following example shows modifying the bandwidth on a path option for bandwidth override. Path-option 3 is changed to an explicit path with a bandwidth of 100 kbps. Path-option 4 is configured with bandwidth 0.

RFCs

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

—

Technical Assistance

Description

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Feature Information for MPLS Traffic Engineering—LSP Attributes

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

The MPLS Traffic Engineering—LSP Attributes feature is an extension to MPLS TE that provides an LSP Attribute List feature and a Path Option for Bandwidth Override feature. These features provide flexibility in the configuration of LSP attributes for MPLS TE tunnel path options. Several LSP attributes can be applied to path options for TE tunnels using an LSP attribute list. If bandwidth is the only LSP attribute you require, then you can configure a path option for bandwidth override.

In 12.0(26)S, this feature was introduced.

In 12.2(33)SRA, this feature was integrated into a Cisco IOS 12.2SRA release.

In 12.2(33)SXH, this feature was integrated into a Cisco IOS 12.2SXH release.

In 12.4(20)T, this feature was integrated into a Cisco IOS 12.4T release.

Glossary

bandwidth—The difference between the highest and lowest frequencies available for network signals. The term also is used to describe the rated throughput capacity of a given network medium or protocol. The frequency range necessary to convey a signal measured in units of hertz (Hz). For example, voice signals typically require approximately 7 kHz of bandwidth and data traffic typically requires approximately 50 kHz of bandwidth.

bandwidth reservation—The process of assigning bandwidth to users and applications served by a network. This process involves assigning priority to different flows of traffic based on how critical and delay-sensitive they are. This makes the best use of available bandwidth, and if the network becomes congested, lower-priority traffic can be dropped. Sometimes called bandwidth allocation

LSR—label switch router. A Multiprotocol Label Switching (MPLS) node that can forward native Layer 3 packets. The LSR forwards a packet based on the value of a label attached to the packet.

MPLS TE—MPLS traffic engineering (formerly known as "RRR" or Resource Reservation Routing). The use of label switching to improve traffic performance along with an efficient use of network resources.

subpool—The more restrictive bandwidth in an MPLS traffic engineering link. The subpool is a portion of the link's overall global pool bandwidth.

TE—traffic engineering. The techniques and processes used to cause routed traffic to travel through the network on a path other than the one that would have been chosen if standard routing methods had been used. The application of scientific principles and technology to measure, model, and control internet traffic in order to simultaneously optimize traffic performance and network resource utilization.

traffic engineering tunnel—A label-switched tunnel used for traffic engineering. Such a tunnel is set up through means other than normal Layer 3 routing; it is used to direct traffic over a path different from the one that Layer 3 routing could cause the tunnel to take.

tunnel—A secure communication path between two peers, such as two routers.

Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)

Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.